
Recovery and Reuse of Nitric Acid Waste in the Plating Process
We use nitric acid to strip off and remove copper and nickel that has adhered to plating jigs and plating tanks at the Shinko Electric Industries Co., Ltd. Wakaho plant, and process that acid as liquid waste containing dissolved metals.
By purifying and concentrating this liquid waste using a diffusion dialysis method, we made it possible to recover and reuse the nitric acid. As a result, we were able to reduce the amount of nitric acid used by about 1,000 tons per year.